Projectile 3D Model doesn't work when export to Minecraft (But works properly in MCreator)

I have been having this problem for a while and have no idea how to fix this.

I created a 3D Projectile model as usual, and it works properly when I test-run it from Mcreator.

However, when I export the exact mod into Minecraft, the 3D model disappears.

In this example, I have this Golem throwing a giant boulder at me as it attacks

Run on Mcreator (works properly): https://imgur.com/a/b2Hjc17

Export to Minecraft (Doesn't work): https://imgur.com/a/3WumAPs

This happens with any other 3D Projectile too, like other bosses and Ranged weapons projectile

Is anyone having this same problem? Any advice would be much appreciated